Add contributing guidelines

CONTRIBUTING.md

@@ -0,0 +1,53 @@
+Good pull requests - patches, improvements, new features - are a fantastic
+help.
+
+If you've spotted any small, obvious errors and want to help out by patching it,
+that will be much appreciated.
+
+If your contribution involves a significant amount of work or substantial
+changes to any part of the project, please open a "contribution enquiry" issue
+first to check that the work is wanted or matches the goals of the project.
+
+All pull requests should remain focused in scope and avoid containing unrelated
+commits.
+
+Please follow this process; it's the best way to get your work included in the
+project:
+
+1. [Fork](http://help.github.com/fork-a-repo/) the project.
+
+2. Clone your fork (`git clone
+   git@github.com:<your-username>/<repo-name>.git`).
+
+3. Add an `upstream` remote (`git remote add upstream
+   git://github.com/<upsteam-owner>/<repo-name>.git`).
+
+4. Get the latest changes from upstream (e.g. `git pull upstream
+   <dev-branch>`).
+
+5. Create a new topic branch to contain your feature, change, or fix (`git
+   checkout -b <topic-branch-name>`).
+
+6. Create the needed tests to ensure that your contribution is not broken in the future.
+   If you are creating a small fix or patch to an existing feature, just a simple test
+   will do, if it is a brand new feature, make sure to create a new test suite.
+
+7. Make sure that your changes adhere to the current coding conventions used
+   throughout the project - indentation, accurate comments, etc.
+
+8. Commit your changes in logical chunks; use git's [interactive
+   rebase](https://help.github.com/articles/interactive-rebase) feature to tidy
+   up your commits before making them public. Please adhere to these [git commit
+   message guidelines](http://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html)
+   or your pull request is unlikely be merged into the main project.
+
+9. Locally merge (or rebase) the upstream branch into your topic branch.
+
+10. Push your topic branch up to your fork (`git push origin
+   <topic-branch-name>`).
+
+11. [Open a Pull Request](http://help.github.com/send-pull-requests/) with a
+    clear title and description.
+
+If you have any other questions about contributing, please feel free to contact
+me.

site/index.html

@@ -40,6 +40,10 @@ <h2>Change Log</h2>
       <h2>Contributors</h2>
 
       {{ AUTHORS }}
+
+      <h2>How to contribute</h2>
+
+      {{ CONTRIBUTING.md }}
 
       <h2>License</h2>